Cutting it fine

With wire EDM now used in new markets, such as aerospace and medical, its role in UK manufacturing is very much increasing in prominence. In this article, Andrew Spence, sales manager at Fanuc UK, explains the role of wire EDM and debunks some common misconceptions.

What is wire EDM?

Often referred to as ‘spark machining’, EDM uses electrical discharges to create a desired shape. Crucial to form intricate parts from hard materials, EDM has become integral to the manufacturing process of many application-critical components, such as surgical equipment and car parts.

There are three types of EDM: wire EDM, sinker EDM and fast hole drilling EDM. With wire EDM, electrodes run through a wire which then form the sparks to cut the material into a desired shape. Over recent years, it has built up a reputation as a precise, efficient and cost-effective machining method and as an alternative to milling , it can cut hard materials to an extremely accurate degree, producing sophisticated parts for a range of industries.

However, there are cases where manufacturers have shown – in my view, misplaced – concern or hesitation, when considering wire EDM. Here, I have broken down four of the most common myths.

Accuracy vs speed

One of the biggest perceived barriers when it comes to wire EDM is the decision of choosing between accuracy and speed. As UK manufacturers continue to be pushed to capacity, they require machining which can be both fast and reliable. Fortunately, this isn’t the case, as Fanuc’s R&D team has developed its EDM technology to ensure a high surface finish can be produced quickly and accurately.

This is because wire EDM machines can be left unmanned for up to 140 hours, allowing manufacturers to extend machining hours to effectively run 24/7 production. This means processes can start on a Friday evening, with the wire EDMs running and producing precise components ready for Monday morning.

Additionally, the benefit of wire EDM is that it offers multi-workpiece machining, allowing manufacturers to load a number of materials to be cut at the same time. Machines can also be programmed to complete the cutting of different components through multi-workpiece machining, saving manufacturers time when having to complete large orders.

Rewiring takes too long

Another concern that manufacturers have often had when it comes to wire EDM is the time taken to thread the wire. While there may be concerns that rethreading can be as frustrating as trying to re-thread cotton into a needle, Fanuc Robocut wire EDMs are capable of automatically rewiring in as little as 10 seconds.

Fanuc’s Automatic Wire Feed (AWF3) threading technology enables fast, reliable automatic threading – the latest AWF3 will connect the wire in thickness of up to 500mm fully submerged. What’s more, wires are cut electrically, leaving a pointed end that is absolutely straight and burr-free, which can also be applied on soft wire. This ensures that minimal disruption to the manufacturing process occurs, alleviating concerns of bulk orders not being met due to the wiring being out of place.

Wire EDM isn’t cost-effective

The next misconception is all about cost and this isn’t just related to wire EDM. Automation has a stigma attached to it that it is too expensive and costs too much to run. While the initial cost may seem large on paper, the payback period for manufacturers can be as little as 18 months.

Where wire EDM is concerned, the actual cost of running the machines is around £5/hour which can be reduced further with cheaper wires. The benefit of incorporating these machines into the manufacturing process is that they can be left unmanned, freeing up personnel to conduct other jobs in the factory.

Fanuc’s Robocut for example can be left to operate on its own, thanks to the combination of its pre-determined CNC drive systems which help to guide the wire into making the desired complex shapes. Significant operator time can also be saved using the Core Stitch function; only one visit to the machine is necessary to remove the waste core.

Not skilled enough to operate

The final myth to debunk is manufacturers’ concerns that they aren’t skilled enough to operate EDMs. Implementing the processes, and utilising the CNC drive systems can sometimes feel overwhelming, but in reality operators can become proficient in less than a week.

Ensuring that you select an EDM from a manufacturer that offers training is vital, as it helps ensure that you are fully equipped with introducing the machine into your operations. Fanuc for example, offers training at its UK headquarters in Antsy Park, Coventry, ensuring that customers aren’t left in the dark when purchasing the industrial machine.

EDM and automation

As discussed, EDMs have an important role to play in the automation of a manufacturing facility. With uptake continuing to increase, the role they can play on the production line can help manufacturers increase their levels of output and operate out of the usual manufacturing hours.

The benefit of being able to leave the machines running over a weekend without the requirement of human interaction should be seen as a positive, but unfortunately, misconceptions surrounding automation in the UK continues to be a sticking point for some manufacturers. Indeed, the UK is still struggling to keep pace with the rest of Europe when it comes to automation in manufacturing.

Many of the concerns and arguments are built on automation replacing people, yet the reality is they offer manufacturers the opportunity to upskill people in new areas and allow them to operate a number of machines simultaneously.

The advantages of wire EDM are clear: they provide a complex, precise cut with low running costs, allowing manufacturers to operate out-of-hours and complete greater orders. The versatility of the machines means they can be implemented for a range of uses, from the smallest medical devices to building blocks for an aeroplane.

As industry faces pressure to complete a growing number of orders in order to compete with overseas manufacturers, UK companies shouldn’t overlook wire EDM and automation as a solution to achieving quality output.

Fanuc’s wire EDM service will be on show at its UK open house event in October 2019. For more information, please visit the website below.

Fanuc www.fanuc.eu